Introduction

Industrial PCs come with stringent requirements that are not satisfied by generic PCs. It is customary for builders to use active cooling in order to ensure that the components are in proper working order. Ventilation slots are also provided to keep airflow up. Chassis size is also not always a concern. However, these flexibilities are not always possible in industrial PCs. Operating environments for such systems usually call for passive cooling, dust resistance, rugged nature and minimal size (read, mini-ITX).

We reviewed the Aleutia Relia last year. Today, we are adding another fanless Ivy Bridge PC to the list, the Habey BIS-6922. The unit was launched late last year. Unlike units meant for the traditional PC market, embedded and industrial units are more focused on long term support and reliability rather than the latest and greatest that the silicon vendor has to offer. So, it is not surprising that Ivy Bridge-based industrial computers are seeing a strong presence in the market only now, after long-term validation by the manufacturers. The high level specifications of the BIS-6922 are available in the launch piece. In the table below, we have a quick overview of the configuration of the review unit sent by Habey.

Our review unit came with the above internal configuration. In addition, we had the installation disk for a OEM copy of Windows 7 Professional x64, a 60 W DC power adapter, mounting plates with screws and a driver and utility CD. I wonder why companies bother with these optical discs when the product itself carries no optical drive. With Flash becoming more economical day-by-day, it might make better sense to bundle these in a USB stick instead of a CD or DVD.

The first section of the review will deal with the setup impressions and teardown of the system. We will take a close look at the thermal design. This is followed by results from our performance evaluation. The numbers will help up get an idea of the relative performance of the unit compared to other PCs with low power consumption. A separate section on thermal performance is also included.

Motherboard Features & Thermal Design

The unique nature of the BIS-6922 is evident in the chassis design. While other fanless PCs such as the Aleutia Relia go in for a rectangular design with hard edges and fins to blend in with it, the Habey fanless unit opts for a curved design on either side. The chassis is made to act as a heat sink and the circular metal segments on either side are serrated. This gives more surface area for heat to dissipate compared to the rectangular fins found in other fanless configurations. Habey terms this 'ICE-FIN'. It also delivers a distinctive look to the unit.

The BIS-6922 has no ventilation holes. Even the power button in the front panel is protected by a sealed plastic cap on the rear side of the front panel. This makes the unit almost fully dust-proof. Despite the dust-proof nature, the unit is very easy to take apart. The underside panel is held by only one screw, It provides access to a mini-PCIe and SIM card slot (for 3G / 4G data connectivity).

The ridged top panel can be easily removed to reveal the heat dissipation mechanism. The 2.5" disk drive is mounted on the underside of this top panel. The top panel has a groove on each side which lines up with similar grooves on the sides of the chassis. We have liberal thermal paste applied to copper heat pipes that are placed in the grooves to improve the thermal conductivity between the chassis sides and the top panel.

After disconnecting the SSD wires from the motherboard, it is possible to completely remove the top panel from the main chassis. This enables us to get a better view of the thermal solution and also some interesting motherboard features. These include PCIe / PCI lanes brought out to the edge of the motherboard (which is unfortunately not usable with the BIS-6922's chassis configuration) and an additional mPCIe slot for a Wi-Fi/BT card or mPCIe SSD. An mSATA port is also available. One of the two SODIMM memory modules (Super Talent / DDR3-1333) is also visible (The other one is partially visible after removing the panel on the bottom).

The motherboard is based on the QM77 chipset. This provides various features targeting business, embedded and industrial PC applications including Intel AMT and support for vPro processors amongst other features.

The CPU and PCH are placed on the motherboard in such a way that a single rectangular block of metal covers both of them. The block has two grooves out of which copper heat pipes swathed in thermal paste emerge to make contact with the inner sides of the chassis (one heat pipe to each side). The contact of these heat pipes with the sides is firmed up thanks to another set of smaller metal blocks. Compared to the heat pipes with a liberal number of bends in the Aleutia Relia, the thermal design configuration of the BIS-6922 is very simple and straightforward. Does this design lead to better thermal performance? Before finding that out, let us take a look at the performance numbers and power consumption of the unit.

Performance Metrics

The BIS-6922 review unit's i7-3720QM has the HD4000 GPU inside, and its performance with respect to HTPC metrics is quite well known. Given the target market of the system, we will not comment on its HTPC capabilities any further in this review. Instead, we just present benchmark numbers from our standard test suite for low power desktops / industrial PCs. Note that some of the benchmarks are pretty recent (such as x264 v5.0 and 3D Mark 2013). Loaner samples haven't been tested with these new benchmarks. Therefore, the list of PCs in each graph are not the same.

Windows Experience Index:

Similar to the Aletuia Relia, the BIS-6922 also scores 6.6 in the Windows Experience Index. It is primarily held back by the performance of the HD4000 GPU. On deeper analysis, we find that the Intel SSD 330 scores lower in the primary disk category compared to the Relia's Crucial mSATA SSD.

The SSD is easily swappable if the user desires, and Habey is also pretty flexible in responding to particular customer requirements with respect to various components. That said, the Intel SSD 330 is definitely good enough for casual desktop use. Most industrial PC applications are not disk-intensive, so the SSD 330 at default is not a bad choice for the BIS-6922.

Futuremark Benchmarks:

Miscellaneous Benchmarks:

Power Consumption and Thermal Performance

The power consumption at the wall was measured with the display being driven through the HDMI port. In the graphs below, we compare the idle and load power of the BIS-6922 with other low power desktop / industrial PCs. For load power consumption, we ran Furmark 1.11.0 and Prime95 v27.9 together.

One of the unfortunate aspects of the Aleutia Relia was that the unit ended up getting throttled when subject to heavy loading even at room temperature (72 F). It is definitely challenging to cool 45W TDP processors in a mini-ITX sized chassis, and Aleutia had to get back to the drawing board after our findings were published. After that exercise, I was looking forward to evaluating other fanless PCs in order to gauge their thermal performance under heavy loading. Our custom fanless Ivy Bridge HTPC managed to do quite well, but it was in a ATX-sized chassis.

Habey is not new to the fanless game, and their experience shows in the choice of processor for the BIS-6922 review sample. While the i7-3770T used in the Aleutia Relia and the i7-3720QM used in the BIS-6922 both have a 45W TDP, we find that the former's TCASE is 70C (TJUNCTION around 75C) and the latter has a TJUNCTION of 105C. This gives the cooling system more leeway to operate without throttling the processor.

We conducted thermal testing by fully loading up both the CPU and the GPU for 18 hours. The room temperature varied between 74 F and 78 F during the duration of the test. Power consumption at the wall was recorded for the first 90 minutes or so (and we found that it settled down to around 67 W beyond that). Unlike the Aleutia Relia where thermal throttling was activated and resulted in power consumption at the wall going down after some time, we find that there is no thermal throttling at play in this system. The load and CPU frequencies were presented in the Relia review, but we won't present them here since the load stayed at 100% and the frequency of the cores was always at 2.594 GHz throughout the course of the stress test.

The average of the temperatures of the four cores of the CPU is presented in the graph above. The maximum junction temperature of the Core i7-3720QM is 105 C, and the BIS-6922 cooling mechanism was able to keep it under that without throttling the CPU. We find that it did touch 105 C once, but the temperature was gradually pulled down without throttling the clocks. On one hand, this makes us a bit worried about the possibility of throttling when the ambient temperature exceeds 80F or so. On the other hand, the above experiment was conducted with the unit placed on the floor in a closed room without any forced air flow. At higher surrounding temperatures, it is definitely advisable to ensure some sort of air flow over and around the unit to help with the cooling process. Habey indicated that the unit could be operated even with the ambient at 50 C, though we suppose they don't expect their customers to run artificial CPU and GPU loading programs to stress the system for days together.

Another interesting aspect is how fast the unit is able to get back to the idle temperature after removal of the processor load. The graph below shows that the unit gets back to the 45C (within 10C of the idling temperature) within 60 minutes.

We conclude this section with a thermal profile of the case after 18 hours of being subject to full CPU and GPU loading. Temperatures are noted in the format (F / C).

Concluding Remarks

Passively cooled high performance PCs are not easy to design and bring to the market. Creating a dust-proof enclosure is also a big challenge. By successfully rising up to these two challenges, Habey manages to hit a home run with the BIS-6922. The choice of chipset and processor as well as the design of the motherboard lend themselves well to the target market. In terms of the performance of the review unit, we would have liked to see DDR3-1600 SODIMM, considering that the Ivy Bridge platform supports it officially. A SSD with higher performance wouldn't have hurt either.

The review unit was not without its problems, though. The power brick (Great Wall brand) bundled with the unit was rated for 60W DC output. Full loading of the unit drew close to 67W. Habey indicated that they don't expect consumers to fully load both the CPU and GPU and stress the power adapter to that extent. We found that the power brick also developed a very audible whine after prolonged use at medium loads. Habey later sent us a 100W power brick (a no-name Chinese OEM model) as replacement and it doesn't seem to be suffering from the whine issue as yet.

The nice aspect about Habey's BIS-6922 is the ability for consumers to customize the components extensively. Components of a particular brand / model can be requested, be it for the DRAM or the SSD or the PSU. I strongly recommend prospective customers to request a power brick from a reputable manufacturer while configuring the system (Seasonic and Delta Electronics come to mind as adapters that have held up well in our labs). Unlike most other manufacturers, Habey doesn't sell units off-the-shelf. Due to the extent of customization that most of the target market requires, an inquiry needs to be placed on their website in order to initiate a purchase order.

In conclusion, the BIS-6922 is the most powerful and efficient passively cooled PC in the mini-ITX form factor that we have seen. Other than the fact that the end user needs to be a bit careful in selecting some of the components, we have little to complain about.